Some People say, that the border goes over the main summit, so the main summit is the highest point of Italy and France. So otherwise MBdC must be the highest summit of Italy which mustn´t be shared with an other country. In my map, the border goes around main summit and courmayeur, so that both peaks are on the french site of the border. Mont Maudit is in my map really shared. I think it is very difficult to say, because everybodys opinion is based on other secondary literature. Perhaps it is like Matterhorn, the border runs over the top, but the highest point is in Switzerland.

In the french maps the frontier runs from the Bosses ridge (p.4740 m) across the rocks to the Brouillard ridge and then to the top of Mont Blanc de Courmayeur. Then it leads to the direction of Mont Maudit.
So Mont Blanc is the highest french peak and MB de Courmayeur the highest italian peak.
I hope that there will not develop a conflict between these contries... ;-)

Well we all know the French version. This does not help.
Again, where is the border officially? Where does the watershed run? I am curious...for me it is not a given thing that the border runs through MtdC.
I have seen plenty of errorous maps, border shifting, wishfull thinking and stuff like that.

I think the official definition is the reference unless someone proves w/o doubt the opposite.

At least mentioning the dispute would not hurt. The statement "highest in Italy" is a strong one, and I would make sure that I can back it up. At least Summitpost should try to remain geographically correct.